@mixin whb($w:500px,$h:500px,$b:red){
    width: $w;
    height: $h;
    background: $b;
}

p{
    @include whb(200px,200px,blue);
    color: red;
}

.app{
    @include whb();
    border-radius: 50%;
}

.cont{
    @include whb($b:yellow);
    width: 100px;
}

li{
    @include whb($h:200px,$w:200px,$b:green);
}
